1. Field of the Invention
The present invention relates to joiner's tools and more particularly, to a door lockset mounting tool for guiding installation of a lockset in any of a variety of door panels.
2. Description of the Related Art
When a worker or user wishes to install a door lockset in a door panel, he/she may adhere a positioning sticker, which is contained in the purchased door lockset, to the door panel, and then defines the front drilling center and the side drilling center subject to the marks at the positioning sticker, and then use a drill to drill holes on the door panel for mounting the door lockset. This positioning sticker is easy to use. However, inaccurate positioning of the positioning sticker on the door panel may affect the performance of the installed door lockset. Further, the side hole mark on the positioning sticker is not adjustable subject to different door panels having a different thickness.
There is also known an L-shaped positioning plate for guiding the installation of a lockset, as shown in FIG. 1. According to this design, the L-shaped positioning plate 80 has a front hole 82 and a side hole 84. When in use, the L-shaped positioning plate 80 is secured to the door panel 12, and then a hole saw 86 is used to make holes on the door panel 12 corresponding to the front hole 82 and side hole 84 of the L-shaped positioning plate 80. This L-shaped positioning plate 80 does not allow the user to adjust the position of the side hole 84 to fit different door panels having a different thickness.
Further, U.S. Pat. No. 4,280,776 discloses a door lockset mounting tool, entitled “Apparatus for installation of a door lockset.” According to this design, the apparatus comprises a drill guide for use during the installation of locksets in doors. The guide has a base body with preferably two recesses formed on the flat faces of opposite sides of the guide. One of the recesses has a flat base for straight-edged doors and the other has a sloped base for beveled-edged doors. An aperture extends through the base body from recess to recess and is centered relative to the recesses so that the flat face serves as a guide for drilling pilot holes on the face of the door, while the recesses selectively serve as self-centerable guides for drilling pilot holes for either straight- or beveled-edged doors. A drift punch can be inserted into the edge pilot hole after the face hole has been made so that upon closing the door and urging the drift punch into the jamb, a mark will be made which is the center of the strike hole. This apparatus is functional; however, the operation procedure of this apparatus is complicated.